Typewriter ribbon spool



Nov. 22, 1960 Filed Feb. 15, 1960 H. J. BIEDINGER TYPEWRITER RIBBON SPOOL 2 Sheets-Sheet l INVENTOR. HENRY. J.BIEDNGER ATTORNEV NOV. 22, 1960 J BIEDlNGER 2,961,084

TYPE-WRITER RIBBON SPOOL Filed Feb. 15, 1960 2 Sheets-Sheet 2 INVENTOR. [60 I20 HENRY J. BIEDXNGER ATTO RN EH United States Patent TYPEWRITER REBON SPOOL Henry J. Biedinger, Syracuse, N.Y., assignor to The Syracuse Stamping Company, Inc., Syracuse, N.Y., a corporation of New York Filed Feb. 15, 1960, Ser. No. 8,696

8 Claims. (Cl. 197-175) This invention relates to typewriter ribbon spools, and more particularly to a spool construction adapted to accommodate a trigger and capable of being molded in one piece in a single molding operation.

Heretofore ribbon spools of the type referred to have been fabricated from sheet metal stampings, which when assembled form the flanges and a connecting drum. Provision of a pivoted trigger in such spools to actuate ribbon reversing mechanism has presented no difliculty, because pivot ears for a trigger were readily struck from the sheet metal of one of the various parts of which the spool is assembled.

The present invention is directed to a one piece plastic spool construction which may be molded in a single operation, and in which provision is made for economical assembly of a pivoted trigger. The invention is particularly directed to the construction of a spool which may be molded at low cost and a trigger assembled thereinto, the spool and trigger assembly presenting a complete spool equivalent to sheet metal spools heretofore available but of substantially lower cost, and a more pleasing appearance.

The above and other novel features of the invention will appear more fully hereinafter from the following detailed description when taken in conjunction with the accompanying drawings. It is expressly understood that the drawings are employed for purposes of illustration only and are not designed as a definition of the limits of the invention, reference being bad for this purpose to the appended claims.

In the drawings, wherein like reference characters indicate like parts:

Figure 1 is a fragmentary enlarged top plan view of the spool;

Figure 2 is a fragmentary enlarged bottom plan view of the spool with trigger;

Figure 3 is a sectional view taken on the line 33 of Figure 1;

Figure 4 is a sectional view taken on the line 44 of Figure 1;

Figure 5 is a fragmentary sectional view similar to Figure 4 with the trigger shown in section;

Figure 6 is a perspective view of the trigger;

Figure 7 is a fragmentary top plan view of a modified form of the invention;

Figure 8 is a fragmentary bottom plan view of the form of Figure 7, with the trigger shown;

Figure 9 is a sectional view taken substantially on the line 9-9 of Figure 7;

Figure 10 is a sectional view taken substantially on the line 1010 of Figure 7.

In Figures 1-4 there is shown a typewriter ribbon spool molded in one piece, and having a drum portion 20, apertured as at 21, and spaced integral flanges 22 and 24. Such spools require a trigger 26 in the form of a bell crank lever (see Figures 5 and 6), having an arm 28 which, when uncovered by the last ribbon convolution,

operates the trigger to actuate the typewriter reverse mechanism.

Such a trigger may comprise a metal stamping from which the ribbon actuated arm 28 and the reverse mechanism arm or pad 30 is formed. The stamping is also provided with shaft bearing cars 32 and 34, having punched holes 36 and 38 which may be substantially square to provide free movement on a circular shaft, or circular bosses. The arm 28 and the pad 30 extend at an angle slightly less than a right angle to each other, from the bridge portion 40, the ends of which are bent to form the ears 32 and 34. As shown in Figure 5, the weight of the trigger, when held in the position shown, in reference to the pivot axis is such as to assure gravity operation, or rotation of the trigger counter-clockwise, the instant the arm 28 is released by the last convolution of ribbon uncovering the arm.

In the spool of Figures 14 provision is made to receive such a trigger, by providing an axially extending groove 42 extending clear through the spool wide enough to clear trigger arm 28. The groove 42 is flanked on either side by cylindrical surfaces 44 and 46 concentric with the drum surface, to provide support for the ribbon convolutions. On either side of the surfaces 44 and 46 are grooves 48 and 50 extending clear through the spool from flange to flange. The flanges 2'2 and 24 have enlarged rectangulardike window openings 52 and 54 respectively, which together with the grooves 48 and 50 provide for a punch or core in the molding process which extends downwardly through the window openings 52 and 54, from the mold which forms the outer surface of the flange 22.

On the outer surface of the flange 24 are molded spaced ears 6% and 62 having opposing faces 64 and 66 lying in the plane of the window ends such as 68 and 76. Short bosses l2 and 74 project from said faces 64 and 66 to provide short stub shafts to receive the apertured ears 32 and 34 of the trigger member, as shown in Figure 2. The cylindrical surfaces of the shafts are substantially tangential to the outer end face of the flange 24, and the surfaces 44 and 46 are cut back as at 76 and 73 to the depth of the grooves 48 and 50, to provide clearance for the bridge portion 49 of the trigger, and also to provide clearance during the assembly of the trigger, which assembly is effected by having one of the trigger ears 34 and 32 initially bent at an acute angle as at 34', for insertion into place, after which the car 34 is bent to a. right angle position as shown in Figure 2.

It will be seen that the spool is readily molded in a single molding operation, the mold forming the outer surface of flange 24, and the core extending through the windows from the mold forming the outer surface of flange 22, parting on a plane at least in part lying in the axis of the stub shafts 72 and 74, so that the mold for flange 24, and the core each form a half of the stub shafts 72 and 74 and the portions of the opposing faces 64, 66, 68 and 70 above and below the stub shaft axis respectively. The lower mold also may have projections to form the cutaway portions 76 and 78 below the flanks 44 and 46.

In the form of the spool shown in Figures 71 0, there is also a drum 109, and integral flanges 192 and 104 of the same general shape as shown in Figures l-4. The flange 102 has a rectangular-like Window 106 of greater length than the window 108 of the flange 104. The drum has a groove 116 wide enough to receive the trigger control arm 23 when held back by ribbon convolutions, and cylindrical ribbon supporting flanks 112 and 114 on either side thereof. Grooves 116 and 118 extend clear through the spool to permit a core or punch attached to the mold that forms the outer surface of flange 102 to project clear through to the inside surface of the other flange 104.

On the outer surface of the lower flange are stirrup like members120- and 122, having a boss like exterior and side faces 124 and 126 all formed exteriorly'by suitablecavities in the mold that forms the outer face of the flange 164. The distance between said outer faces 124 and 126 is the same as the length of window 103.

V The lower end of the core or punch that projects through the upper window is provided with rounded tongues to form the U shaped openings 13% and 132 in the stirrups 126 and 122, such tongues extending oppositely to the outer surfaces 124 and 125 of the stirrups, and cooperating with the walls of the stirrup forming cavities of the mold forming the outer surface of flange 194.. The flanks 112 and 11 are cutaway as at 156 and 152 to clear the bridge portion 49 of the trigger when in position as shown in Figure 8, and such cut-away portions of the flanks may be formed by upwardly extending projections on the mold forming the outer surface of the flange 104.

The depth of the U slots 13% and 132 in the stirrups 120 and 122 is such as to bring the half circular bottom thereof approximately a diameter away from the outer surface 16%) of flange 104, or a shade less, whereby when a trigger is located in position, see Figure 8, a shaft 165 may be projected through the shaft stirrups from one side and loosely through the apertured cars 32 and 34 of the trigger as shown in Figure 8. The shaft is of a length somewhat greater than the spacing between the outer surfaces 124 and 126 of the stirrups 12% and 122, so the ends bear upwardly against the outer surface 169 of the flange 104, while portions short of the ends bear oppositely against the semi-circular bottoms of the U slots 130 and 132 of the stirrups. The pin preferably makes a sufliciently snug flt, when in place, so as to assure against its dislodgement.

It will be seen from the foregoing that a plastic spool construction having provision for the ready insertion of a trigger has been shown, that may be molded in one piece in a single operation.

While two forms of the invention have been illustrated and described, it is to be understood that the invention is not limited thereto. As various changes in the construction and arrangement may be made without departing from the spirit of the invention, as will be apparent to those skilled in the art, reference will be had to the appended claims for a definition of the limits of the invention.

, What is claimed is: l. A one piece molded typewriter ribbon spool comprising a drum and integral upper and lower end'flanges,

in the length of the window opening in the upper flange, said drum having a groove extending from one end to the other centrally disposed in respect to said window openings, a bell crank trigger having an arm adapted to lie in said groove, and an arm adapted to lie against the underside of said lower spool flange, and means for pivotally mounting said trigger for rotation on the axis of said cylindrical surfaces.

3. A one piece molded typewriter ribbon spool comprising a drum and integral upper and lower end flanges, said flanges each having aligned window openings partially overlying a part of said drum, spaced bearing bosses integrally formed on said lower end flange adjacent opposite ends of the window opening of the lower flange, each of said bosses having a cylindrical surface facing upward toward the upper flange, said cylindrical surfaces being in axial alignment on an axis adjacent the lower flange, and said axis lying in a plane substantially tangential to said drum, and said surfaces being disposed wholly within the length of the window opening in the upper flange.

4. A one piece molded typewriter ribbon spool comprising a drum and integral upper and lower end flanges, said flanges each having aligned window openings partially overlying a part of said drum, spaced bearing bosses integrally formed on said lower end'flange adjacent opposite ends of the window opening of the lower flange, each of said bosses having a cylindrical surface facing upward toward the upper flange, said cylindrical surfaces being in axial alignment on an axis adjacent the lower flange, and said axis lying in a plane substantially tangential to said drum, and said surfaces being disposed wholly within the length of the window opening in the upper flange, said drum having a groove extending from one end to the other centrally disposed in respect to said window openings, a bell crank trigger having an arm adapted to lie in said groove, and an'arm adapted to lie against the underside of said lower spool said flanges each having aligned substantially rectangular window openings partially overlying a part of said drum, spaced bearing bosses integrally formed on the outside of said lower end flange adjacent the ends of the window opening of the lower flange, each of said bosses having a cylindrical surface facing upward toward the upper flange, said cylindrical surfaces being in axial alignment on an axis below the lower flange, and said axis lying in a plane substantially tangential to said drum, and said surfaces being disposed below and wholly within the length of the window opening in the upper flange;

2. A one piece molded typewriter ribbon spool comprising a drum and integral upper and lower end flanges, said flanges each having aligned substantially rectangular window openings partially overlying a part of said drum, spaced bearing bosses integrally formed on the outside of said lower end flange adjacent the ends of the window opening of the lower flange, each of said bosses having a cylindrical surface facing upward toward the upper flange, said cylindrical surfaces being in axial alignment on an axis below the lower flange, and said axis lying in a plane substantially tangential to said drum, and said surfaces being disposed below and wholly withflange, and means for pivotally mounting said trigger for rotation on the axis of said cylindrical surfaces;

5. A one piece molded typewriter ribbon spool comprising a drum and integral upper and lower end flanges, said flanges each having aligned substantially rectangular window opening partially overlying a part of said drum, spaced bearing bosses integrally formed on the outside of said lower end flange adjacent the ends of thewindow opening of the lower flange, each of said bosses having a short cylindrical stub shaft, said stub shafts extending toward each other and being in axial alignment on an axis below the lower flange and said axis lying in a plane substantially tangential to said drum, and said stub shafts being disposed below and wholly within the length of the window opening in the upper flange.

6. A one piece molded typewriter ribbon spool comprising a drum and integral upper and lower end flanges, said flanges each having aligned substantially rectangular window openings partially overlying a part of said drum, spaced bearing bosses integrally formed on the outside of said lower end flange adjacent the ends of the window opening of the lower flange, each of said bossesha'ving a short cylindrical stub shaft, said stub shafts extending toward each other and being in axial alignment on an axis below the lower flange and said axis lying in a plane substantially tangential to said drum, and said stub shafts being disposed below and wholly within the length of the window opening in the upper flange, said drum having a groove extending from one end to the other centrally disposed in respect to said window openings, 2. bell crank trigger having an arm adapted to lie in said groove, and an arm adapted to lie against the underside of said lower spool flange, and apertured means for pivotally mounting said trigger for rotation on said stub shafts.

7. A one piece molded typewriter ribbon spool comprising a drum and integral upper and lower end flanges, said flanges each having aligned substantially rectangular window openings partially overlying a part of said drum, spaced bearing bosses integrally formed on the outside of said lower end flange adjacent the ends of the window opening of the lower flange, each of said bosses comprising a stirrup having an upwardly facing cylindrical surface, said cylindrical surfaces being in axial alignment on an axis below the lower flange, and said axis lying in a plane substantially tangential to said drum, and said surfaces being disposed below and wholly within the length of the window opening in the upper flange.

8. A one pliece molded typewriter ribbon spool comprising a drum and integral upper and lower end flanges, said flanges each having aligned substantially rectangular window openings partially overlying a part of said drum, spaced bearing bosses integrally formed on the outside of said lower end flange adjacent the ends of the window opening of the lower flange, each of said bosses comprising a stirrup having an upwardly facing cylindrical surface, said cylindrical surfaces being in axial alignment on an axis below the lower flange, and said axis lying in a plane substantially tangential to said drum, and said surfaces being disposed below and wholly within the length of the window opening in the upper flange, said drum having a groove extending from one end to the other centrally disposed in respect to said window openings, a bell crank trigger having an arm adapted to lie in said groove, and an arm adapted to lie against the underside of said lower spool flange, and means for pivotally mounting said trigger for rotation on the axis of said cylindrical surfaces, said means including a shaft extending through said stirrups, and bearing against the underside of said lower flange beyond said stirrups.

References Cited in the file of this patent UNiTED STATES PATENTS 

